<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>

    <style>
      .box1{
          width: 200px;
          height: 200px;
          border: 1px solid red;
          overflow: hidden;/*把超出父元素的部分剪掉*/

      }
      .box1 img{
          width: 100%;
          height: 100%;
    transition: all 1s;
      }
      .box1:hover img{
          transform: scale(1.5);
      }
    </style>
</head>
<body>
    <div class="box1"><img src="../img/img1.jpg" alt=""></div>
</body>
</html>